Check The Signal Waveform Of HO2S

1. IG "OFF". Connect HO2S connector.
2. Engine start.
3. With engine at operating temperature, monitor signal waveform of HO2S with GDS.

   Courtesy of HYUNDAI MOTOR AMERICA

4. Is the sensor switching properly?

YES 

• Go to "Check fuel filter" as follows.

NO 

• Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.